another thought on the subject:

early shotgun receivers were machined from solid blocks or billets of rolled steel.

floor plates, trigger plates and lock plates were no doubt made from sheets of much thinner bar stock.

could it be that the billets of rolled steel were of a different alloy than the thinner bar stock? if so, that could account for the difference in how the case colors developed and appeared on the different parts of the gun?

EDG, if you will look in The Parker Story, the key reference books for Parker enthusiasts, you will see on p. 427 photos of frame forgings and explanation of the hammer forging process.

A person can learn a lot about Parkers, restorations including correct charcoal color case hardening, and what is correct in Parkers, by study of TPS, which was written by experts on the Parker gun and the Charles Parker Company.

Bruce Day, no expert but I've read a lot, learned a lot from experts and been fortunate to have been around a lot of nice Parkers.

Dean,

I Don't want to drift off topic too much, but the picture you posted of your nieces vase is nice. I believe that this piece was Raku fired. This is a process where the clazed piece is fired to temp. and then removed at temp and then placed in a trash can with straw, hay, papers and other organtic materials. It creates a wonderful effect.

There is also an old Native american method called pit firing which is just the bare unglazed clay that is buried in a pit with a fire in other organic mateirals. And left to smolder for days. That process is very unpredictable, but can sometimes yield some great colors.

I was a Ceramic arts major in college. So it is a subject that I am familar with.

No, Ed, Temperatures for any heat treatment are specific to the metallurgy and the end result you want to achieve, not the manufacturer.
Those temps I referenced are typical for most Ni-Cr-Mo alloys with Carbon in the .20% to .30% range

I noticed on the PGCA 2012 raffle gun (10 ga hammer) the side plates retain much more CC than the action. Syracuse LC Smith's also age the same way, more color on the side plates versus the action. It must be the difference in steel and or the CC process. I have been told that the forging process modifies the grain of the metal resulting in some areas retaining cc better than others and some frames holding cc better than others. here is a Smith example of what I am talking about.
http://i156.photobucket.com/albums/t...DSC_0008-2.jpg

Same with the Syracuse Lefevers. The sidelocks/sideplates hold the case color much much better than the the frame does.

Best,

Mike

mike: wonder why that is? ed

Mike, :):)

wonder if one did a rockwell hardness test of harden lock plates and floor plates vs hardened receivers, would one find that the thinner metal lock plates and floor plates would be harder than the receiver...the theory being that thinner bar stock parts would in fact be harder than the thicker roll stock receivers? if so, perhaps harder metal retains case colors better and longer and than does less hard metal...all else being the same, of coarse.

Ed, :):)